Is there a way to paste documented R code into R console or Rstudio without the arrow or plus signs being registered?

Question

This will make more sense with an example. Typical R manuals from CRAN show R code with a line starting with > and indentations indicated with +. See http://cran.r-project.org/web/packages/doMC/vignettes/gettingstartedMC.pdf for an example.

The trouble is that you can't cut and paste that into a console without copying it into an editor and removing those arrow and plus characters. Is there an easier way to execute that text as R code? I figured that somebody must have dealt with this problem. Otherwise, I guess I'll write a script.

Answer 1

The writing has already been done.

2009 post by Duncan Murdoch:

CleanTranscript <- function(lines) {
         lines <- grep("^[[:blank:]]*[^>+[:blank:]]*[>+]", lines, value = TRUE) 
         lines <- sub("^[[:blank:]]*[^>+[:blank:]]*[>+] ?", "", lines) }

source(textConnection(CleanTranscript(
       # This is the Windows input strategy
       readLines("clipboard")
       # See below for Mac version
                      )), 
                      echo = TRUE, max.deparse.length=Inf) 

Subsequent 2009 R-help post by Gabor Grothendieck:

process.source <- function(action = c("both", "run", "show"), echo = TRUE,
    max.deparse.length = Inf, ...) { 
    # This is the Mac input strategy
    L <- readLines(pipe("pbpaste"))
    #  for Windows devices use
    #  L <- readLines("clipboard")
    rx <- "^[[:blank:]]*[^>+[:blank:]]*[>+]" 
    is.cmd <- grepl(rx, L) 
    L[is.cmd] <- gsub(paste(rx, "?"), "", L[is.cmd]) 
    L[!is.cmd] <- paste("#", L[!is.cmd]) 
    action <- match.arg(action) 
  if (action != "run") for(el in L) cat(el, "\n") 
  if (action == "both") cat("##################################\n") 
  if (action != "show") 
       source(textConnection(L), echo = echo, 
       max.deparse.length = max.deparse.length, ...) 
invisible(L) }

Note: The upvotes prompted me to post this as a "feature request" on the RStudio Discussion Board. Although I have not broken it yet, it might need more testing if it were to be built in to the RStudio framework.